Surface treatment of organic polymers



United States Patent 3,535,145 SURFACE TREATMENT OF ORGANIC POLYMERS William G. Gowdy, Cherry Hill, N..l., and Joseph W. Keil, Midland, Mich, assignors to Dow Corning Corporation, Midland, Mich., a corporation of Michigan No Drawing. Application Nov. 12, 1965, Ser. No. 507,549, now Patent No. 3,453,248, dated July 1, 1969, which is a continuation-in-part of application Ser. No. 452,921, May 3, 1965, which in turn is a continuation-in-part of application Ser.'No. 405,570, Oct. 21, 1964. Divided and this application Oct. 23, 1968, Ser. No. 770,121 Int. Cl. B41m 1/18 US. Cl. 11769 23 Claims ABSTRACT OF THE DISCLOSURE The surface characteristics of vinylic polymers are altered by the application of an organosilicon compound containing at least one HSR'SiE moiety, where R is a divalent hydrocarbon radical free of aliphatic unsaturation, followed by application of heat or actinic radiant energy. Alternatively, the organosilicon compound can be added to the molten vinylic polymer and this composition is further processed, for example, by extruding into fibers. Exemplary is an acrylonitrile butadiene styrene surface which has been treated with and irradiated with ultraviolet light which exhibits improved lubricity.

This application is a divisional of application Ser. No. 507,549, now US. Patent 3,453,248, filed Nov. 12, 1965, which is a continuation-in-part of application Ser. No. 452,921, filed May 3, 1965, now abandoned, which in turn is a continuation-in-part of application Ser. No. 405,570, filed Oct. 21, 1964, now abandoned.

This invention relates to a new method of treating the surfaces of solid organic polymers which have been prepared by vinylic polymerization.

The object of this invention is to provide a means for altering the surface characteristics of these polymers. This invention provides a means for making polymer surfaces which are oleophobic, hydrophobic, hydrophilic, receptive to inks and dyes, having high lubricity, or of low lubricity, as desired.

For example, considering the vinylic polymer polyethylene: solvent-resistant containers can be made from polyethylene which has been provided with an oleophobic surface. Polyethylene having an aminofunctional, hydrophilic surface is receptive to permanent printing and dyeing. Additionally, polyethylene sheets can have their surfaces altered so as to have a high coeflicient of friction against other treated polyethylene sheets, making the sheets more easily handleable in bulk.

A great number of other applications are possible with this invention, a number of which are described below.

Most broadly, this invention relates to the process of (l) applying to the surface of a solid, vinylic polymer a film comprising a fluid organosilicon compound, free of aliphatic unsaturation, containing at least one HSRSiE moiety, where R is a divalent hydrocarbon radical free of aliphatic unsaturation, and (2) applying 3,535,145 Patented Oct. 20, 1970 energy to the surface of said vinylic polymer, whereby said organosilicon compound is irreversibly attached to said vinylic polymer.

Any solid, vinylic polymer is suitable for use in this invention. By vinylic polymer is meant any organic polymer which is formed by the polymerization of aliphatically unsaturated carbon-carbon bonds, such as those found in the vinyl group. Examples of such polymers are polyethylene, polypropylene, poly(acrylonitrile-butadienestyrene), polystyrene, polymethylmethacrylate, poly (acrylonitrile-styrene), polyisobutene, polyvinyl chloride,

polyvinylacetate, poly (vinylchloride-vinylidene chloride), and the organic rubber such as natural rubber, ethylenepropylene-cyclohexadiene terpolymer, styrene-butadiene rubber, and butadiene-acrylonitrile rubber.

R can be any divalent hydrocarbon radical, free of aliphatic unsaturation, such as the methylene, dimethylene,

trimethylene, isobutylene hexamethylene, octadecamethylene, cyclohexylene,

l CH2CHCH2, or crn-O-omomradicals. The isobutylene, trimethylene, and dimethylene radicals are especially desirable.

The organosilicon compound must be fluid, e.g., it must be a liquid, a vapor, or applied as a solution or an emulsion.

The nature of the organosilicon compound used in this process is not critical, so long as there is at least one HSR'SlE moiety present in the molecule. The nature of the surface produced on the vinylic polymer varies with the type of organosilicon compound used.

For example, the organosilicon compound can be a hydrolyzable organosilane. One embodiment of this invention is the process of (1) applying to the surface of a solid, vinylic polymer a film consisting essentially of a composition selected from the group consisting of (a) silanes of the formula (HSR) R SiX and partial hydrolyzates thereof, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of alpihatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, m has an average value of 1 to 3, n has an average value of to 2, the sum of m and n being from 1 to 3, and X is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation; and (2) applying energy to the surface of said vinylic polymer, whereby (a) is irreversibly attached to said vinylic polymer.

R can be any monovalent hydrocarbon or halohydrocarbon radical free of aliphatic unsaturation such as the methyl, ethyl, isobutyl, cyclohexyl, octyl, tetradecyl, octadecyl, phenyl, diphenyl, Z-phenylpropyl, tolyl, 3,3,3- trifluoropropyl, 4-chlorooctyl, bromocyclohexyl, dichlorophenyl, or bromophenyl radicals. Examples of R are shown above.

More than one type of R or R group can be found in the silicones used in this invention.

X can be any hydrolyzable group, free of aliphatic unsaturation, known to the art, e.g., alkoxy groups such as methoxy, ethoxy, isopropoxy, hexoxy, or 2-ethylhexoxy; halogen groups such as chlorine or bromine; acyloxy groups such as the formate, acetate, or butyrate groups; ketoxime groups such as ON0, or

ON O; or the isocyanate group.

Examples, therefore, of suitable silanes for use in this invention are CHzCH2 and Cl Silanes containing no hydrolyzable groups such as HSCHzCHCH2Si(CH3)a are also usable in this invention to provide a hydrophobic surface.

Heat or actinic radiant energy can be applied to the 7 vinylic polymer surface, in accordance With step (2) of the above-described process, in a number of ways. The method of applying the energy is not critical, though some methods give better results than others.

The vinylic polymer surface can be heated in the absence of air to provide adequate energy to cause the organosilicon compound to permanently bond to the vinylic polymer.

Another preferred method of applying energy is to apply ultraviolet radiation to the solid vinylic polymer surface which has the organosilicon compound thereon. There is a specific ultraviolet dosage for each vinylic polymer-siloxane system that gives the best results for the desired purpose. There is no known way to theoretically calculate this optimum dosage for a given system, but some workable dosages are shown in the examples below. Effective dosages generally lie between 5 and 40 minutes if the organic polymer is 6 inches from a standard ultraviolet lamp.

Other methods of applying energy are through the use of gamma radiation, or peroxide catalysts coupled with heat.

Upon the application of energy to the vinylic surface which is silicone-coated, it is believed that the mercaptan groups on the organosilicon molecules react with linkages in the vinylic polymer in the following manner to form a chemical bond between the polysiloxane and organic polymer:

After this reaction, the organosilicon compound is believed to be chemically attached to the vinylic surface so that washing with solvents for the organosilicon compound cannot remove them. Such solvent-washing is a good test for whether or not the silicone is actually bonded to the vinylic polymer.

The process of treating vinylic polymer surfaces with the above-described hydrolyzable silanes finds an important utility as an intermediate step in the preparation of altered surfaces on vinylic polymers. An example of this is the process of (1) applying to the surface of a solid, vinylic polymer a film consisting essentially of a composition selected from the group consisting of (a) silanes of the formula (HSR) R SiX and partial hydrolyzates thereof, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, in has an average value of 1 to 3, n has an average value of 0 to 2, the sum of m and n being from 1 to 3, and X is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation, (2) applying energy to the surface of said vinylic polymer, whereby (a) is irreversibly attached to said vinylic polymer, and (3) applying to the same surface of said vinylic polymer a film of (b) a composition selected from the group consisting of and partial hydrolyzates thereof,

and partial hydrolyzates thereof, silicic acid, and partial condensates of silicic acid, where R is any alkylene radical of no more than 4 carbon atoms, x is a positive integer, Q is selected from the group consisting of hydrogen and -R NH groups, and the other symbols are as defined above.

R" can be any alklene group as described above, such as methylene, dimethylene, trimethylene, and

These materials of (b) above are believed to react with the hydrolyzable groups of the mercapto silanes of (a), thereby being bonded to the surface of the vinylic polymer. The materials of (a) and (b) can be added to the vinylic polymer simultaneously, if desired, preferably in proportions of 1 to 75 mol percent of (a) and 25 to 99 mol percent of (b).

The compositions of the formula and their partial hydrolyzates, impart oleophobicity to the vinylic polymer surface when applied in the manner described above. x preferably has a value of 4 to 14.

The compositions of the formula and their partial hydrolyzates, render the vinylic polymer surface hydrophilic. Water-soluble dyes, inks, and printing pastes, such as polyamide resins that contain pigments, can be permanently aflixed to such a treated surface, making possible the dyeing of thermoplastic fibers and printing on thermoplastic sheets.

Finally, silicic acid and the partial condensates thereof dry on the polymer to produce what is essentially a silica surface bonded to the vinylic polymer. This increases the coefficient of friction of the vinylic polymer, which is useful where sliding is undesirable.

Another useful additive to the mercaptosilane-treated surface of a vinylic polymer is a polyglycol which is endblocked with a functional group that reacts with the hydrolyzable groups on the vinylic polymer surface. Hydrophilic or slightly hydrophobic surfaces can be produced in this manner.

Catalysts can be used to accelerate the reaction of the above materials with the mercaptosilane-treated surface if desired, e.g., KOH, FeCl stannous octoate, trihexylamine, and other known catalysts for the hydrolysis and condensation of silanes that contain hydrolyzable groups.

The term applying to the surface carries With it the requirement that the organosilicon compound so applied should be found on the surface in detectable amounts, e.g., as a film of polysiloxane.

The organosilicon ingredient can be applied to the vinylic polymer surface in a direct or an indirect manner; in other words, not only can the organosilicon ingredient be directly applied by conventional means to the surface of the vinylic polymer, but it can also be added to the molten vinylic polymer so that it is dispersed therein. This latter technique is particularly useful with saturated hydrocarbon polymers, e.g., polypropylene.

A particularly useful product of this latter technique is a composition consisting essentially of a mixture of (a) 100 parts by weight of a thermoplastic, saturated vinylic polymer and (b) from 0.01 to 1.4 parts by Weight of an organosilicon compound selected from the group consisting of silanes of the formula and partial hydrolyzates thereof, where R is selected from the group consisting of monovaleut hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, m has an average value of 1 to 3, n has an average value of 0 to 2, the sum of m and n being from 1 to 3, and X is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation.

It has been found that these compositions are surface reactive in the manner of the various mercaptoalkylsilane-coated, saturated polymers shown above, and that surface properties similar to those shown above can be attained. These compositions also tend to have higher heat distortion temperatures and more resistance to cold flow than their mercaptoalkylsilane-free counterparts. They also appear to exhibit other improvements in physical properties as well as those mentioned above.

The above compositions can be utilized to make dyeable fibers by the process of (1) Extruding one of the above mercaptoalkylsilanecontaining vinylic polymers into fibers and (2) Applying to said fibers a Water dispersion containing from 0.1 to 50 weight percent of a priming composition selected from the group consisting of colloidal silica, a silane of the formula and partial hydrolyzates of said silane, where R is selected from the group consisting of monovaleut hydro carbon and halohydrocarbon radicals free of aliphatic unsaturation, R" is an alkylene radical of no more than 4 carbon atoms, X is selected from the group consisting of the hydroxyl group and hydrolyzable groups, Q is selected from the group consisting of hydrogen and --R"NH groups, m has an average value of 1 to 3, and n has an average value of 0 to 2, the sum of m and n being from 1 to 3, whereby a dyeable fiber is produced.

Examples of the various symbols and ingredients are shown above.

It should be noted that the aminoalkylsilane or its hydrolyzates, which must be present in order to render the fiber dyeable, must be applied within a few minutes or hours after preparation of the mercaptoalkylsilane-containing vinylic polymer. If this does not happen, the vinylic polymer will often become nonadherent to the aminoalkylsilane and therefore not permanently dyeable.

Alternatively however, a dispersion of colloidal silica can be applied to the silane-containing vinylic polymer. The vinylic polymer will then remain adherent indefinitely toward all organosilicon compounds which contain silanol or hydrolyzable groups, including the aminoalkyl silanes used herein. The mercaptoalkylsilicone-containing fibers can therefore be stored for a long time and/or heated without the problem of degradation of the aminoalkylsilane primer on its surface. They can then be later treated with the aminoalkylsilane and dyed.

The preferred vinylic polymers for making fibers as described above are polyethylene, polypropylene, and copolymers thereof.

The above process can be commercially exploited by adding the mercaptoalkylsilane ingredient, or its hydrolyzate, to the molten hydrocarbon polymer prior to extrusion, and by placing the colloidal silica or the aminoalkyl silicone into the quenching bath into which the fibers are immediately drawn after extrusion. Only a few minor modifications are therefore required to adapt the presently existing production lines for hydrocarbon polymer fibers to perform the process of this application.

Another embodiment of this invention is the process of (l) applying to the surface of a solid, vinylic polymer a film of a fluid siloxane polymer having a viscosity of at least 45 cs. (centistokes) at 25 C., which consists essentially of units and where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical, free of aliphatic unsaturation, n has an average value of from 1.8 to 2.2, in has an average value of 1 to 3, and k has an average value of to 2, the sum of m and k being no more than 3, and there being an average of at least 2 (b) units and at least 5 times as many (21) units as (b) units per siloxane polymer molecule; and (2) applying energy to the surface of the organic polymer, whereby the siloxane polymer is attached to the vinylic polymer surface, forming a permanent lubricant thereon.

By permanent it is meant that siloxane coating cannot be washed off the vinylic polymer with a solvent for the siloxane without also removing the outer surface of the organic polymer.

The fluid siloxane polymer generally needs a viscosity of at least 45 cs. at 25 C. in order to keep from soaking into the organic polymer, thereby leaving the polymer surface, but with some organic polymers, lower viscosity siloxanes can be used.

The upper viscosity limit of the siloxane is not critical, the only requirement being that the siloxane be spreadable on the organic polymer. It is preferred, however, for the siloxanes used to have a viscosity of below 5000 cs. at 25 C.

It is also preferable in this case for the organic polymer to be an organic rubber, examples of which have been given above. Examples of R and R are also shown above.

The preferred siloxane is a linear dimethylsiloxane polymer with (IE3 (-ObEiRSII) CH groups as endblocking units.

It is also especially preferred for the siloxanes used to have viscosities of 100 to 1,000 cs. at 25 C.

A preferred method of applying energy to mercaptosiloxane-treated polymers is to heat the organic polymer,

preferably rubber, to the vulcanizing temperature in a mold, using the polysiloxane of this invention as a mold release fluid. The resulting product is a vulcanized, molded article with permanent lubricity on its surface due to the fact that at least some of the siloxane is bonded to the organic polymer.

Little difliculty with the silicone concentration will be encountered if it is placed on the vinylic polymer in pure, undiluted form; however, solutions and emulsions can often be used to apply the silicone to the vinylic polymer surface.

The mercaptosilicones of this invention are generally known to the art, and can be made in a number of ways.

Mercapto-endblocked polysiloxanes can be made by equilibrating cyclic polysiloxanes containing the desired R groups with a mercapto-disiloxane of the formula in the presence of an acid clay catalyst, where the symbols are as defined above.

The above mercapto-disiloxanes can be made by hydrolyzing the appropriate mercapto-silane containing a silicon-bonded hydrolyzable group such as the chlorine group.

Another way of making mercapto'endblocked polysiloxanes is to react hydroxyl-endblocked polysiloxanes containing the desired R groups with a compound of the formula l ClIaObiiltSlI R Where R and R are defined above, in the presence of stannous octoate. Methanol is evolved as a byproduct.

A way of making any mercapto-siloxane used in this invention is to cohydrolyze silanes containing only R groups and hydrolyzable groups with silanes containing RSH groups, or to equilibrate cyclic siloxanes containing only R groups with polysiloxanes containing RSH groups.

The inercaptosilanes, which can be used by themselves or which can be used to make the mercaptosiloxanes of this invention, can be made as follows: when it is desired for the mercapto group to be separated from the Si atom by 1 or 3 carbon atoms, the appropriate terminal chloroalkyl compound can be reacted with NaSH e.g.:

| o In 0 Ha When it is desired for 2, 4 or more carbon atoms to separate the mercapto group from the silicon atom, the appropriate terminal olefin can be reacted with thioacetic acid, e.g.

0 CH3 ll CH3 0 CI'IaCSl'I I ll ClIaOlI CIIaOSiCH:CHz OIIeObiiCIIzCIIzSCCII;

Na. H; CH3

CH (EH3 H CHaOSiCIhCHzSH CHaOCCIIfl Other known methods also exist for making the above silanes.

The following examples are illustrative only and should not be construed as limiting the invention which is properly delineated in the appended claims.

EXAMPLE 1 The following rubber formulation was prepared in parts by weight:

Parts Styrene-butadiene rubber stock 23.8 Polybutadiene rubber stock 16.2 High surface area silica 20.2 Zinc oxide 1.7 Coumarone-indene resin 3.4 Sulfur 0.8 Stearic acid 0.34 Altax rubber additive 0.4 Methyl Tuads additive 0.07

A polysiloxane of the formula CH3 CH3 CH3 11s CH:SiO(SiO)-zl iCIIzSH Ha H3 H3 having a viscosity of about -60 cs. at 25 C., was used in the following experiment.

The lubricity of the rubber samples was tested by the 9 Crock test where a /2-inch ball bearing is rubbed back and forth in a 6-inch path at about 60 strokes. per minute, the weight of the ball bearing on the rubber being 1.5 pounds. The time of failure is the time until the rubber begins to crack and abrade.

(a) The above rubber formulation was vulcanized for 45 minutes at 160 C. and 5,000 p.s.i. It was then wiped with isopropyl alcohol. After minutes of the Crock test, the rubber showed severe abrasion.

(b) The above rubber formulation was vulcanized as in (a), and then the polysiloxane was applied. The treated rubber withstood 4 hours on the Crock tester Without abrasion. However, similarly treated rubber was cleaned with isopropyl alcohol and tested on the Crock tester. After 5 minutes, there was severe abrasion.

(c) The above rubber formulation was vulcanized as in (a), but the polysiloxane was used as a mold release (e) The rubbers of (a) and (c) were tested for their physical characteristics with the following results:

Tensile strength at break Elongation, Rubber Durometer point percent EXAMPLE 2 agent. The vulcanized rubber was cleaned with isopropyl ple follow:

TABLE Tensile, Elongation, Crock test Rubber Treatment Durometer p.s.i. percent time to failure Natural None 81 2,060 510 sec.

Do Siloxane mold release" 85 2, 010 500 4 hr. 30 nun Ethylene propylene cyclohexadieu one 91 3, 260 510 30 sec.

Do SlloXane mold release. 90 3,180 500 24 hr tadiene rubber mixed one 87 2, 515 520 1 min. 88 2, 550 510 12 hrs. 97 3,550 285 2 min. 97 3, 450 290 8 hrs. 83 3, 860 400 1 min 85 3, 680 410 24 hrs 88 1, 850 650 20 see. 0 87 1, 800 675 min Styrene-butadiene rubber 84 2, 910 500 sec.

D 3, 000 535 35 min alcohol and tested on the Crock tester. After 4 hours there EXAMPLE 3 was moderate abrasion on the rubber.

(d) The above rubber formulation was vulcanized for 1 hour at 175 C. and 5,000 p.s.i., using the above siloxane as a mold release agent. The vulcanized rubber was cleaned with isopropyl alcohol and tested on the Crock tester. After 4 hours there was no abrasion on the rubber.

Standard formulations of the following rubbers were 40 vulcanized as in Example 2 with the polysiloxanes shown below used as mold release agents. The polysiloxanes and rubbers used, and the lubricity obtained, are shown below. The samples were washed in isopropyl alcohol before testing in the Crock tester (described in Example 1).

TAB LE Crock test Rubber Siloxane polymer time to failure CH CH3 CH (a) Styrene-butadieue rubber mixed with polybutadiene H S i0 S i0) S iH 4 hr CH3 CH3 CH3 100 cs. at 25 0.

CH3 CH3 CH3 (b) Styrene-butadiene rubber mixed with polybutadiene-.. H S CH2 S i0 S i0) -20 S iCHz S H 12 hrs.

CH3 CH3 CH3 52 cs. at 25 0.

CH3 CH3 CH3 (c) Styrene-butadiene rubber mixed with polybutadieue H S CH2 S i0 (S i0) -15!) IS iCHz S H 12 hrs.

CH3 CH3 CH3 400 cs. at 25 C.

(d) Ethylene-propylene-cyclohexadiene terpolymer The siloxane of (a). 1 hr. (e) Ethylene-propylene-cyclohexadiene terpolymer The s loxane of (0). 24 hrs. (f) Styrene-butadiene rubber The s loxane of (a). 1 min. (g) Styrenebutadiene rubber The s loxane of (b). 1 hr. (h) Styrene-butadiene rubber The siloxane of (c). 1 hr.

(3H3 (IJHQ, CH3 (i) Styrene-butadiene rubber (HS CH2CHCHzSiO])z(S i0)-; 0 3 hrs.

CH3 CH3 400 cs. at 25 C.

(j) Butadiene-aerylonitrile rubber (low nitrile) The siloxane of (a). 3 hrs. (k) Butadiene-acrylonitrile rubber (low nitrile) The s loxane of (b). 24 hrs. (1) Butadiene-acrylonitrile rubber (low nitrile) The siloxane of (c). 24 hrs.

1 This is a comparison run, It and the others below show the superiority of mercaptosiloxanes to a siloxane containing the SiH functional group,

1 1 Example 4 12 the panels were irradiated with ultraviolet light. They were then wiped with isopropyl alcohol and tested to failure in the Crock test of Example 1.

The results follow:

The following vulcanized rubber samples were thinly coated with mercapto-siloxanes and treated with ultraviolet light from a standard U.V. lamp. The irradiated TABLE Crock test Substrate Siloxane used Irradiation time to failure (a) Polyethylene None None 1 min. (b) Polyethylene Dimethylpolysiloxane, 350 es. at 25 0. do min.

(3H (IJHQ i a (e) Polyethylene (HS CHZCHCHZSlOi/Z) -1(S iO)n do 5 min.

CH C 3 440 es. at 25 C.

(d) Polyethylene The siloxane of (e) 5 min. of U.V. light, 6 in. from U.V. source min. (e) Polyethylene .1 The siloxane of (c) min. of U.V. light, 6 in. from U.V. source 35 min. (i) Areylonitrile-butadiene styrene... None None 5min.,

(g) Acrylonitrile-butadiene styrene. The siloxane of (e) 15 min. of U.V. light, 6 in. from U.V. sourcc 22 min.

products were washed in isopropyl alcohol and tested by the Crock test of Example 1. The results follow:

TABLE Crock test time to Rubber Siloxane used Irradiation failure (a) Natural None None see.

(311 (3H (IJ (1)) Natural (HS CH2CHCH2?iO1I2)2(siO)n 5 min. of ultraviolet, G in. from U.V. 15 min.

source. CH3 CH3 440 es. at C. (0) Natural The siloxane of (b) 15 min. of ultraviolet, 6 in. from U.V. 4 hrs.

source. r r ((1) Natural (HS OH2?l0l/2)2(? i0) 11 l0 4 hrs.

CH CH 51 es. at 25 C. (e) Styrene-butadiene rubber None 45 see. (I) Styrene-butadiene rubbe The siloxane of (b) from U.V. 5 min.

source. (g) Styrene-butadiene rubber The siloxane of (b) min. of ultraviolet, 6 in. from U.V. 30 min.

source. (11) Ethylenepropylene-cyclohexadiene terpolymer None None 30 sec.

15 min. of ultraviolet, 6 in. from U.V. 10 min.

source. 30 min. of ultraviolet, 6 in. from U.V. 16 hrs.

(i) Ethylcnepropylene cyelohexadiene terpolymer... The siloxane of (b) (j) Ethylenepropylene cyclohexadiene terpolyrner... The siloxane of (b) source.

(k) Ethylenepropylene eyclohexadiene terpolymcn- The siloxane of ((1) do 1 hr.

(l) Styrene-butadiene rubber with polybutadiene None None 1 min.

(n1) Styrene-butadiene rubber with polybutadiene The siloxane of (b) 15 min. of ultraviolet, 3 in. from U.V. 5 min.

source.

(11) Styrene-butadiene rubber with polybutadiene. The siloxane of (b) 30 min. of ultraviolet, 3 in. from U.V. 1 min.

source.

(0) Styrenebutadienc rubber with polybutadienc The siloxane of (b) 30 min. of ultraviolet, 6 in. from U.V. 30 min.

source.

(p) Styrene-butadieno rubber with polybutadiene... The siloxane of (b) 1 hr. of ultraviolet, G in. from U.V. 2min.

source.

(q) Butyl None None 20 see.

(r) Butyl The siloxane of (d) 30 min. of ultraviolet, 6 in. from U.V. 1 niin.

source.

]This indicates that there has been an overdose of ultravio et.

=T1ie pull needed to remove Scotch tape from the rubber Example 5 Steel panels primed with added films of the mercapto-siloxanes shown below, and 75 of (q) was 750 gms. The pull needed to remove Scotch tape from the rubber of (r) was about half of this: 400 gins. This clearly indicates the presence of a surface lubricanit.

EXAMPLE 6 When natural rubber is coated with a fluid polysiloxane consisting essentially of mol percent (SIiO) units CH3 55 mol percent units, and

mol percent [(HsOflH13)3SiOl/2] units there being an average of 2 mercaptosiloxy groups per molecule, a rubber possessing permanent lubricating characteristics at its surface is formed on exposure of the coated rubber to about 2 megarads of gamma radiation in the period of an hour.

EXAMPLE 7 When crystalline polypropylene resin is coated with a fluid polysiloxane consisting essentially of approximately (3H3 69 mol percent SIiO )units C|12H5 25 mol percent SIiO units Ci2H25 1 mol percent (CHsSiOs/z units 2 mol percent(OS|iC1eHa SH) units and (IJHa 3 mol percent [OflzSKCmHasSHh having a viscosity of 5,000 cs. at 25 C., and when this coated resin is heated at 150 C. with infrared radiation in argon gas for one hour, a permanent lubricating coating on the surface of the resin is formed.

EXAMPLE 8 When solid ethylene-vinyl acetate copolymer is coated with a fluid polysiloxane of the average formula (1H3 ([1113 wmO-cmcmnol/mtsiom SH CH3 and exposed to ultraviolet light for 20 minutes at a 6 inch distance from the U.V. source, the resin acquires permanent lubricity.

EXAMPLE 9 When polystyrene resin is coated with a fluid polysiloxane of the average formula and exposed to 30 minutes of ultraviolet light at a 6-inch distance from the U.V. source, the resin acquires permanent lubricity.

EXAMPLE 10 A 1 weight percent solution of a partial hydrolyzate of nsomoms noonm in toluene was wiped on polypropylene yarn of 210. denier and 35 count. This was then dried in the air and exposed for 10 minutes to an ultraviolet lamp at a distance of 3 inches.

Following this, a 10 weight percent solution of in isopropanol was wiped on the yarn, and the yarn was dried at 260 F. for 5 minutes.

EXAMPLE 11 (a) A thin film of HSCHzCHCH2Si(O 011m was wiped on a sheet of polyethylene, which was then exposed for 10 minutes to an ultraviolet lamp at a distance of 3 inches.

A thin film of 3,3,3-trifluoropropyltrimethoxysilane was then applied to the treated polyethylene surface, and allowed to stand for a few minutes. The surface was then Washed with acetone to remove unattached silanes and allowed to dry.

The contact angle of a drop of mineral oil on the treated polyethylene surface was 20. This indicated moderate oleophobicity.

The contact angle of a drop of mineral oil on an untreated polyethylene surface was found to be 0, indicating no oleophobicity.

The contact angle of a liquid drop on a surface is the angle between the surface and the side of the drop where it contacts the surface, and is a measure of the compatibility of the materials that make up the drop and the surface.

(b) The above experiment was repeated, replacing 3 ,3 ,3-trifluoropropyltrimethoxysilane with The contact angle of a drop of mineral oil on polyethylene treated in this manner was 45 indicating strong hydrophobicity.

(c) A polyethylene container was treated in the manner of (b) above, and was found to be suitable for containing oils for a long period of time.

EXAMPLE 12 A thin film of HSCHiCHCHzSKOCHaM was wiped on a sheet of polyethylene, which was then exposed for 10 minutes to an ultraviolet lamp at a distance of 3 inches. Treated sheets of mercaptosilane-grafted polyethylene resulted.

A thin film of was wiped on the treated polyethylene and dried.

To this there was applied a polyamide coating resin which is useful as a printing paste (Versamide 940). The adhesion of the resin to the coated polyethylene was ex cellent, with no adhesive failure under severe flex.

The experiment was repeated, omitting the mercaptosilane treatment, but including the treatment with the aminosilane.

The adhesion of the polyamide coating resin to the polyethylene was poor.

EXAMPLE 13 Two polyethylene sheets, treated with mercaptosilane as in Example 12, were coated with an aqueous dispersion of colloidal silica (a partial condensate of silicic acid), and were then allowed to dry. They were then washed in water to remove excess silica and dried again.

The sheets were placed on top of each other with their treated sides in contact, and a 125 g. weight was placed on top of both.

The upper sheet was then pulled laterally along the bottom sheet. 120 g. of force was required to start the sheets moving, indicating that the treated surfaces had a starting coefricient of friction of 0.96.

Untreated polyethylene sheets, when tested as above, began moving relative to each other at 65 g. of pull, showing that their starting coefficient of friction was 0.52.

The treated polyethylene sheets of Example 12 showed a coefficient of friction of 0.36 upon similar testing.

EXAMPLE 14 The mercaptosilane-treated polyethylene of Example 12 was treated with an ethylene-propylene polyglycol copolymer (Pluronic L 61) which was endblocked by reaction with 011201101120CH2CH2CH2Si(OCH3)3 The terminal hydroxy group of the polyglycol reacts with the silane epoxy group to graft the molecules together.

This treated polyethylene was allowed to dry for 10 minutes, and the excess, unbonded material was washed off with isopropanol.

The dried polyethylene was tested for water-compatibility. The contact angle of a drop of water on the treated polyethylene surface was 0, indicating that the surface was hydrophilic.

Untreated polyethylene has a contact angle with water of 45 EXAMPLE 15 When a ring of butadiene-acrylonitrile rubber is coated with CzHa CHa 2 and dried in the presence of ultraviolet radiation, coating of the same ring with any of the following compounds, in the presence of gentle heating, will result in an oleophobic rubber ring which is resistant to swell in organic solvents:

( oF19CH2CH2S|iGlz (b) A partial llydrolyzate of (C4FQCH2CH2) 1Si(0 C2H z.

CzIIis (c) (C F3CH2CH2)3SiONC ((1) A partial hydrolyzate of C F CH2CH2S|i(OCH3)2.

EXAMPLE 16 When strips of polystyrene are treated in the presence of ultraviolet radiation with CH3 (u) which is cocondensed with any of the following compounds, polystyrene strips which are receptive to water soluble dyes and inks are produced:

(a) (CHsO)aSiCH2CH2CH2NH2 (b) A partial hydrolyzate of (CHaO)2S|iCHzCH2CH2NHCH2CH2N H (0) 0 Hail 0S1 (CHzCHCHzNHz)3 (d) A partial hydrolyzate of ON OS iCH2CH2NHCHNH2 C H; C H2 C 211 EXAMPLE 17 (a) To 2 samples of molten polypropylene there was added 0.1 to 0.5 weight percent, respectively, of

HSCH CH Si OCH The silane was dispersed in the polypropylene, and the mixture was extruded into fibers. The fibers were immediately quenched in a 1.7 weight percent water solution of NH CH CH NH(CH Si( OCH The treated, dried fibers were washed in isopropanol, dried and dipped in a 1 weight percent water solution of Cibalon Red 2 GL dye. The fibers were then dried for 5 minutes at 260 F. to yield a richly-colored polypropylene.

The dyed fibers were washed for three automatic washer cycles with hot water and Tide detergent. The color of both sets of fibers was unfaded at the termination of this treatment.

(b) The above experiment was repeated using polypropylene without a mercaptoalkylsilane. The dyed fibers made from this material faded badly during the washing test.

EXAMPLE 18 The experiment of Example 17(a) was repeated, using a molten polypropylene which contained 0.5 weight percent of a hydrolyzate of HSCHzCHz KO CHa)2 The same excellent results as above were achieved.

EXAMPLE 19 When a mixture of parts by weight of molten polypropylene and one part of HSCHz(|JHCHzSi(O CzH5)3 is extruded into fibers which are quenched in a 5 weight percent emulsion of colloidal silica, the resulting fibrous product exhibits excellent fastness to water-soluble dyes when they are treated shortly before dyeing with NH CH CH CH Si OCH EXAMPLE 20 When a mixture of 100 parts by weight of molten poly (ethylene-propylene) copolymer and one part by weight of ll HS CH2CIIzCHzSi(OCCHa)z is extruded into fibers which are then dipped in a 20 weight percent water solution of a partial hydrolyzate of CHaNHCHsCHCHaSKNHz):

The resulting fibrous product is permanently dyeable with water-soluble dyes.

That which is claimed is:

1. The process of (1) applying to the surface of a vinylic polymer a fluid organosilicon compound, free of aliphatic unsaturation, containing at least one HSRSiamoiety, where R is a divalent hydrocarbon radical free of aliphatic unsaturation, and

(2) applying heat or actinic radiant energy to the surface of said vinylic polymer, whereby said organosilicon compound is irreversibly attached to said vinylic polymer.

2. The process of claim 1 where the organosilicon compound is selected from the group consisting of silanes of the formula HSR'--),,,R SiX and partial hydrolyzates thereof, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, m has an average value of l to 3, n has an average value of to 2, the sum of m and n being from 1 to 3, and X is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation.

3. The process of claim 2 where X is lower alkoxy.

4. The process of claim 2 where R is an alkylene radical of no more than 4 carbon atoms.

5. The process of claim 2 where the organosilicon compound is HSCHzCHCHzSKOOHtDa 6. The process of claim 2 where the vinylic polymer is polyethylene.

7. The process of claim 2 where the vinylic polymer is polypropylene.

8. The process of claim 2 where m is 1.

9. The process of claim 2 where n is 0.

10. The process of claim 2 where the energy is heat.

11. The process of claim 2 where the energy is ultraviolet light.

12. The process of claim 1 where the organosilicon compound consists essentially of a cocondensate of from 1 to 75 mol percent of (a) (HSR') R SiX and from 25 to 99 mol percent of (b) a compound selected from the group consisting of and partial hydrolyzates thereof,

and partial hydrolyzates thereof, silicic acid, and partial condensates of silicic acid, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation,

R is a divalent hydrocarbon radical free of aliphatic unsaturation, in has an'average value of 1 to 3, n has an average value of O to 2, the sum of m and n being from 1 to 3, X is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation, R" is any alkylene radical of no more than 4 carbon atoms, x is a positive integer, and Q is selected from the group consisting of hydrogen and --R"NH groups. 13. The process of claim 12 where (b) is (CH O) SiCH CH CH NHCH CH NH 14.. The process of claim 12 where (b) is x Zx+lCH2GH2)m X4-m-n and where x has a value of from 4 to 14.

15. The process of claim 1 where the organosilicon compound is a fluid siloxane polymer having a viscosity of at least 45 cs. at 25 C., which consists essentially of (a) (RnSi0 units,

and

where R is selected from the group consisting of monovalent hydocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical, free of aliphatic unsaturation, n has an average value of from 1.8 to 2.2, m has an average value of 1 to 3 and k has an average value of 0 to 2, the sum of m and k being no more than 3, and there being an average of at least 2 (b) units and at least 5 times as many (a) units as (b) units, per siloxane polymer molecule. 16. The process of claim 15 where R is C Ha 17. The process of claim 15 where the vinylic polymer used in an organic rubber.

18. The process of claim 15 Where step (2) is performed by means of directing ultraviolet light on the organic polymer surface.

19. The process of claim 15 where the siloxane is a linear dimethylsiloxane polymer with (IJHa (OSIiRSH) CH3 groups as endblocking units, where R is a divalent alkyl radical.

20. The process of (1) applying to the surface of a vinylic polymer a compound selected from the group consisting of (a) silanes of the formula (HSR'),,,R,,SiX.,

and partial hydrolyzates thereof, where R is selected from the group consisting of monovalent hydrocrabon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, In has an average value of 1 to 3, n has an average value of 0 to 2, the sum of m and n being from 1 to 3, and x is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation, (2) applying heat or actinic radiant energy to the surface of said vinylic polymer, whereby (a) is irreversibly attached to said vinylic polymer, and (3) applying to the same surface of said vinylic polymer (b) a compound selected from the group consisting of (C xF'lrl-l CH2CH2)mSiX4-m-n It. and partial hydrolyzates thereof,

X4-m-nSi(R"NHQ,)m

and partial hydrolyzates thereof, silicic acid, and

1 9 partial condensates of silicic acid, where R" is any alkylene radical of no more than 4 carbon atoms, or is a positive integer, Q is selected from the group consisting of hydrogen and R"NH groups and the other symbols are as defined above. 21. The process of claim 20 where (b) is (OxF2X+lCII2CII2)mfiiX4-mn where x has a value of from 4 to 14.

22. The process of claim 20 Where (b) is (a) (RnsiOl units, and 2 the free valences of the S atoms being attached to atoms selected from the group consisting of hydrogen and carbon atoms bonded to the vinylic polymer, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, n has an average value of from 1.8 to 2.2, 111 has an average value of 1 to 3, and k has an average value of 0 to 2, the sum of m and k being no more than 3, and there being an average of at least 2 (b) units and at least 5 times as many (21) units as (b) units per siloxane polymer molecule.

References Cited UNITED STATES PATENTS 3,170,940 2/1965 Johnston 204-159.l3 X 3,186,965 6/1965 Plueddemann 260824 X 3,317,461 5/1967 Plueddemann 260824 X ALFRED L. LEAVITT, Primary Examiner J. H. NEWSOME, Assistant Examiner US. Cl. X.R.

ll793.3l, 138.8, 161; 204-159.l3; 260825, 79.5 

